Today’s Western society is undergoing rapid change, and the speed of this process of change seems to be increasing. One of the major social changes is the gradual changeover from daily lives that contained high levels of physical effort to lives that are increasingly sedentary. A sedentary lifestyle is not without its problems. Several common illnesses are related to physical inactivity. Athletics, exercise, outdoor life and trend sports must be regarded as expressions of lifestyle and not as logical responses to an absence of physical activity. After puberty, there appears to be a genetic need to save energy and not to exert ourselves unnecessarily. There is also no doubt that children’s and young people’s sports habits, along with the general trends in the present child-rearing culture, are becoming institutionalized to an greater extent. Organized sports carry much of the burden of children’s and young people’s sports activities. Spontaneous sports, especially traditional team sports, have decreased. The number of children and young people who are inactive in sports has increased over the past few decades, and many of these children do not compensate with other physical activity such as cycling, walking or playing outdoors. Keywords: organized sports; physical activity; sedentary lifestyle; social changes; spontaneous sports